So-called head-up display systems are available for use in military fighter planes. U.S. Pat. No. 6,161,062, for example, relates to a display system for the pilot of a plane, using a head-up display. Via the head-up display, for instance, an artificial horizon is blended in for the pilot, as well as flight data, such as ones concerning flight altitude and speed, which are recorded by sensors.
U.S. Pat. No. 4,775,218 and U.S. Pat. No. 5,572,203 relate to the problem of the correct superimposition of symbols to be projected in a military plane. To solve this problem, among other things, optical systems are proposed, having a laser beam for the appropriate correction of the representation.
In vehicles, such as motor vehicles, on the other hand, the representation of information for the driver is generally performed via the dashboard and via the display of a navigation system. It may be a disadvantage, in this regard, that the driver has briefly to divert his glance from the road, in order to absorb the corresponding information.
U.S. Pat. No. 5,519,536 relates to a warning system for the display of information on a head-up display in a vehicle. Such a warning is displayed, for example, when a minimum distance from a preceding vehicle is undershot, the size of the displayed warning indication increasing as the distance decreases.
The system for driver assistance of U.S. Pat. No. 5,969,969 detects objects in the surroundings of the vehicle, and generates from that appropriate information for the driver. This information can be displayed on a head-up display.
Various head-up display systems are also in U.S. Pat. No. 5,719,567 and U.S. Pat. No. 5,801,667.